Pick up the correct statement from the following :

• The water level in a still well, represents the ground water table level
• The difference between water table level and the water level in a well after pumping, is called depression head
• The surface of water table surrounding a well during pumping, forms a cone of depression
• The distance from the centre of the well up to the place where level of water table is not affected, is called radius of influence
• All the above.